Method and System for Uniformly Applying a Multi-Phase Cleaning Solution to a Substrate

ABSTRACT

A system for cleaning a substrate includes a carrier and a cleaning station. The carrier is capable of holding the substrate and is movably coupled to a pair of guide tracks extending a length of the system. The cleaning station includes a force applicator and a gate. The force applicator has an applicator length and is operatively coupled to the cleaning station. The force applicator is rotatable and is adjusted to a first height off the surface of the carrier as the substrate is being cleaned. The force applicator has a hollow structure with internal channels and openings dispersed throughout the applicator length to dispense cleaning solution to substrate surface. The gate is affixed to a trailing edge of the force applicator and is set to a second height off the surface of the carrier. The gate includes a gate length that at least spans the applicator length.

CLAIM OF PRIORITY

This application is a Divisional application of U.S. patent applicationSer. No. 13/028,091, filed on Feb. 15, 2011, entitled “Method and Systemfor Uniformly Applying a Multi-Phase Cleaning Solution to a Substrate,”which is a Divisional application of U.S. patent application Ser. No.11/395,851 filed on Mar. 30, 2006, (since issued as U.S. Pat. No.7,913,703) entitled “Method and Apparatus for Uniformly Applying aMulti-Phase Cleaning Solution to a Substrate,” which (1) claims thebenefit of U.S. Provisional Application No. 60/755,377, filed Dec. 30,2005, and (2) is a continuation-in-part of prior application Ser. No.10/608,871, filed Jun. 27, 2003, and entitled “Method and Apparatus forRemoving a Target Layer from a Substrate Using Reactive Gases.” Thedisclosure of each of the above-identified applications is incorporatedherein by reference.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is related to U.S. patent application Ser. No.10/816,337, filed on Mar. 31, 2004, and entitled “Apparatuses andMethods for Cleaning a Substrate,” now U.S. Pat. No. 7,441,299; U.S.patent application Ser. No. 11/153,957, filed on Jun. 15, 2005, andentitled “Method and Apparatus for Cleaning a Substrate UsingNon-Newtonian Fluids,” U.S. patent application Ser. No. 11/154,129,filed on Jun. 15, 2005, and entitled “Method and Apparatus forTransporting a Substrate Using Non-Newtonian Fluid,” U.S. patentapplication Ser. No. 11/174,080, filed on Jun. 30, 2005, and entitled“Method for Removing Material from Semiconductor Wafer and Apparatus forPerforming the Same,” U.S. patent application Ser. No. 10/746,114, filedon Dec. 23, 2003, and entitled “Method and Apparatus for CleaningSemiconductor Wafers using Compressed and/or Pressurized Foams, Bubbles,and/or Liquids,” now U.S. Pat. No. 7,648,584; U.S. patent applicationSer. No. 11/336,215, filed on Jan. 20, 2006, entitled “Method andApparatus for removing contamination from a substrate,” U.S. patentapplication Ser. No. 11/346,894, filed on Feb. 3, 2006, entitled “Methodfor removing contamination from a substrate and for making a cleaningsolution,” and U.S. patent application Ser. No. 11/347,154, filed onFeb. 3, 2006, entitled “Cleaning compound and method and system forusing the cleaning compound.” The disclosure of each of theabove-identified related applications is incorporated herein byreference.

BACKGROUND

In the fabrication of semiconductor devices such as integrated circuits,memory cells, and the like, a series of manufacturing operations areperformed to define features on semiconductor wafers (“wafers”). Thewafers include integrated circuit devices in the form of multi-levelstructures defined on a silicon substrate. At a substrate level,transistor devices with diffusion regions are formed. In subsequentlevels, interconnect metallization lines are patterned and electricallyconnected to the transistor devices to define a desired integratedcircuit device. Also, patterned conductive layers are insulated fromother conductive layers by dielectric materials.

During the series of manufacturing operations, the wafer surface isexposed to various types of contaminants. Essentially any materialpresent in a manufacturing operation is a potential source ofcontamination. For example, sources of contamination may include processgases, chemicals, deposition materials, and liquids, among others. Thevarious contaminants may deposit on the wafer surface in particulateform. If the particulate contamination is not removed, the deviceswithin the vicinity of the contamination will likely be inoperable.Thus, it is necessary to clean contamination from the wafer surface in asubstantially complete manner without damaging the features defined onthe wafer. However, the size of particulate contamination is often onthe order of the critical dimension size of features fabricated on thewafer. Removal of such small particulate contamination without adverselyaffecting the features on the wafer can be quite difficult.

Conventional wafer cleaning methods have relied heavily on mechanicalforce to remove particulate contamination from the wafer surface. Asfeature sizes continue to decrease and become more fragile, theprobability of feature damage due to application of mechanical force tothe wafer surface increases. For example, features having high aspectratios are vulnerable to toppling or breaking when impacted by asufficient mechanical force. To further complicate the cleaning problem,the move toward reduced feature sizes also causes a reduction in thesize of particulate contamination that may cause damage. Particulatecontamination of sufficiently small size can find its way into difficultto reach areas on the wafer surface, such as in a trench surrounded byhigh aspect ratio features or bridging of conductive lines, etc. Thus,efficient and non-damaging removal of contaminants during modernsemiconductor fabrication represents a continuing challenge to be met bycontinuing advances in wafer cleaning technology. It should beappreciated that the manufacturing operations for liquid crystaldisplays (i.e., flat panel displays) suffer from the same shortcomingsof the integrated circuit manufacturing discussed above.

Cleaning methods that use multi-phase cleaning solutions (i.e., foam,emulsions, etc.) that are comprised of a dispersed phase, continuousphase and solids overcome many of the problems associated withconventional wafer cleaning methods. When a force is applied against themulti-phase cleaning solution, the solids dispersed within thecontinuous phase come into contact or interact with the particulatecontaminants on the wafer surface. As the cleaning solution, with thesolids, is removed from the wafer surface the particulate contaminantsare also removed.

There are several inherent challenges with using multi-phase cleaningsolutions to clean wafer surfaces. One is that it is difficult to ensurethat the solution is uniformly applied across the entire wafer surface.Uneven application of the solution may result in an uneven cleaningprofile on the wafer surface due to non-uniform rinsing of the wafersurface. Another is that it is difficult to uniformly apply forceagainst the solution across the wafer surface so that the embeddedsolids actually come into contact with the contaminant particulatesduring cleaning. As discussed earlier, the solids must come within thevicinity of the contaminant particles before they can interact andeffectuate the removal of the particles.

In view of the forgoing, there is a need for an apparatus and method foruniformly applying a multi-phase cleaning solution (i.e., foam,emulsions, etc.) across a wafer surface during the cleaning of the wafersurfaces.

SUMMARY

Broadly speaking, the present invention fills these needs by providingimproved apparatuses, methods, and systems for uniformly applying amulti-phase cleaning solution (i.e., foam, emulsions, etc.) across awafer surface during the cleaning of the wafer surfaces. It should beappreciated that the present invention can be implemented in numerousways, including as an apparatus, a method and a system. Severalinventive embodiments of the present invention are described below.

In one exemplary embodiment, a system for cleaning a substrate havingsurface contaminants thereon, is disclosed. The system includes acarrier and a cleaning station. The carrier is capable of holding thesubstrate and movably coupled to a pair of guide tracks extending alonga length of the system. The cleaning station includes a force applicatorand a gate. The force applicator has an applicator length and isoperatively connected to the cleaning station above a surface of thecarrier and the pair of guide tracks. The force applicator is rotatable.The force application is set to a first height off the surface of thecarrier as the substrate is being cleaned. The force applicator has ahollow structure with a plurality of internal channels and openingsdispersed throughout the applicator length of the force applicator. Thechannels and openings are configured to dispense a cleaning solution toa surface of the substrate. The gate is affixed to a trailing edge ofthe force applicator and is configured to be adjusted to a second heightoff the surface of the carrier. The gate includes a gate length thatextends to at least span the applicator length.

In still another embodiment, a system for cleaning a substrate havingsurface contaminants, is disclosed. The system includes a substratecarrier and a cleaning station. The substrate carrier is capable ofholding the substrate during the cleaning. The cleaning station includesa force applicator and a gate. The force applicator has an applicatorlength and is operatively connected to the cleaning station above asurface of the carrier. The force applicator is configured to rotate andbe adjusted to a first height off the surface of the carrier as thesubstrate is being cleaned. The force applicator includes a hollowstructure with a plurality of internal channels and openings dispersedthroughout the applicator length. The channels and openings areconfigured to dispense a cleaning solution to a surface of thesubstrate. The gate is affixed to a trailing edge of the forceapplicator. The gate is set to a second height off the surface of thecarrier. A gate length of the gate extends to at least span theapplicator length.

Other aspects will become apparent from the following detaileddescription, taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be readily understood by the followingdetailed description in conjunction with the accompanying drawings, andlike reference numerals designate like structural elements.

FIG. 1A is a side view of an apparatus for uniformly applying amulti-phase cleaning solution (i.e., foam, emulsions, etc.) across thesurface of a substrate, in accordance with one exemplary embodiment ofthe present invention.

FIG. 1B shows a top view of the apparatus, in accordance with oneembodiment of the present invention.

FIG. 2A shows a cross-sectional view of a force applicator and gate, inaccordance with one embodiment of the present invention.

FIG. 2B is an illustration showing a side view of a force applicatorwith a straight line baffle pattern, in accordance with one embodimentof the present invention.

FIG. 2C is a depiction of a side view of a force applicator with adiagonal baffle pattern, in accordance with one embodiment of thepresent invention.

FIG. 3A is an illustration of a side view of an apparatus for uniformlyapplying a multi-phase cleaning solution across the surface of asubstrate 108, in accordance with one embodiment of the presentinvention.

FIG. 3B is an illustration showing a top view of an apparatus foruniformly applying a multi-phase cleaning solution across the surface ofa substrate, in accordance with one embodiment of the present invention.

FIG. 4A is an illustration of a side view of an apparatus for uniformlyapplying a multi-phase cleaning solution 110 across the surface of asubstrate 108, in accordance with one embodiment of the presentinvention.

FIG. 4B is an illustration of a top view of an apparatus for uniformlyapplying a multi-phase cleaning solution across the surface of asubstrate, in accordance with one embodiment of the present invention.

FIG. 5A is an illustration of a side view of a plurality of poweredrollers supporting and rotating a substrate as a force applicator andgate uniformly applies a multi-phase cleaning solution across thesurface of the substrate, in accordance with one embodiment of thepresent invention.

FIG. 5B is an illustration of a top view of a set of four poweredrollers supporting and rotating a substrate as a force applicator andgate uniformly applies a multi-phase cleaning solution across thesurface of the substrate, in accordance with one embodiment of thepresent invention.

FIG. 5C is an illustration of a side view of a vacuum chuck used tosupport and rotate a substrate as a force applicator and gate uniformlyapplies a multi-phase cleaning solution across the surface of thesubstrate, in accordance with one embodiment of the present invention.

FIG. 6A is an illustration of a top view of a system for cleaning asubstrate having surface contaminants, in accordance with one exemplaryembodiment of the present invention.

FIG. 6B is an illustration of a top view of a system for cleaning asubstrate having surface contaminants, in accordance with one embodimentof the present invention.

FIG. 6C is an illustration of a side view of a system for cleaning asubstrate having surface contaminants, in accordance with one embodimentof the present invention.

FIG. 7 shows a flow chart of a method for uniformly applying amulti-phase cleaning solution (i.e., foam, emulsions, etc.) across thesurface of a substrate, in accordance with one embodiment of the presentinvention.

DETAILED DESCRIPTION

An invention is described for apparatuses, methods, and systems foruniformly applying a multi-phase cleaning solution (i.e., foam,emulsions, etc.) across a wafer surface during the cleaning of the wafersurfaces. It will be obvious, however, to one skilled in the art, thatthe present invention may be practiced without some or all of thesespecific details. In other instances, well known process operations havenot been described in detail in order not to unnecessarily obscure thepresent invention.

As used herein, a multi-phase cleaning solution includes a continuousphase, dispersed phase and solids which are disseminated throughout thecontinuous phase. In one embodiment, the dispersed phase refers to gasbubbles that are dispersed throughout the continuous phase (e.g., foam).In another embodiment, the dispersed phase refers to liquid dropletsthat are dispersed throughout the continuous phase (e.g., emulsion). Inone embodiment, the dispersed phase provides an intermediary to bringsolids in close proximity with contaminant particles on a substratesurface. For further explanation of the composition of the cleaningsolution and its mechanisms see U.S. patent application Ser. No.11/346,894, filed on Feb. 3, 2006, entitled “Method for removingcontamination from a substrate and for making a cleaning solution,” U.S.patent application Ser. No. 11/347,154, filed on Feb. 3, 2006, entitled“Cleaning compound and method and system for using the cleaningcompound” and U.S. patent application Ser. No. 11/336,215, filed on Jan.20, 2006, entitled “Method and Apparatus for removing contamination froma substrate.” The solids interact with the particles during cleaning toeffectuate their removal. A substrate, as used herein, denotes bothsemiconductor wafers and flat panel display surfaces (e.g., liquidcrystal displays, etc.) that may become contaminated duringmanufacturing operations.

FIG. 1A is a side view of an apparatus for uniformly applying amulti-phase cleaning solution (i.e., foam, emulsions, etc.) across thesurface of a substrate, in accordance with one exemplary embodiment ofthe present invention. As depicted in this embodiment, the apparatusincludes a force applicator 106 and a gate 104. The force applicator 106is configured to apply a force uniformly against the cleaning solution110 as the applicator 106 moves in parallel fashion across the surfaceof the substrate 108. Typically, the force applicator 106 is positionedso that the distance between the applicator 106 and the surface of thesubstrate 108 is between about 0.1 millimeter (mm) and 10 centimeters(cm). The gate 104 is configured to follow the trailing edge of theforce applicator 106 and to substantially planarize the cleaningsolution 110 as it moves across the surface of the substrate 108.Typically, the gate 104 is positioned so that the distance between thegate 104 and the surface of the substrate 108 is between about 0.1 mmand 5.0 mm. In one embodiment, the force applicator 106 and gate 104 arepositioned at about the same distance off the substrate surface.

In one embodiment, the force applicator 106 and the gate 104 areconfigured to operate in unison when moving across the substrate 108.Therefore, as the force applicator 106 and gate 104 moves across thesurface of the substrate 108, the cleaning solution 110 issimultaneously being applied against the surface of the substrate 108and planarized so that the solution 110 assumes a uniform thicknessprofile on the substrate surface. In another embodiment, the forceapplicator 106 moves independently from the gate 104.

As depicted in the present embodiment, the force applicator 106 is inthe shape of a cylindrical drum and positioned so that the axis ofrotation of the applicator 106 is parallel to the surface of thesubstrate 108. It should be understood that the force applicator 106 cantake any shape so long as the applicator 106 can be utilized touniformly apply a cleaning solution 110 to the surface of a substrate108. In one embodiment, the force applicator 106 is a solid and smoothstructure without any internal cavity regions. In another embodiment,the force applicator 106 is a hollow structure with internal channelsand multiple openings dispersed throughout the surface of the applicator106. The channels and openings being configured to dispense a cleaningsolution 110 or other liquids to the surface of the substrate 108 duringcleaning operations. In one embodiment, the force applicator 106 is madeout of polyvinyl alcohol (PVA) foam. Some examples of other materialsthat the applicator 106 can be made out of include polymers (e.g.,Teflon™, polyvinyl alcohol, polyurethane, polytetrafluoroethylene,polyethylene terephthalate, polyvinylidine difluoride,polyetheretherketone, polyvinyl chloride, etc.), rubber, ceramics,stainless steel, tool steel, and aluminum. It should be appreciated thatthe force applicator 106 can be made out of essentially any material solong as the material is non-reactive with the cleaning solution 110 andcan function to uniformly apply a force against the solution 110 on thesurface of a substrate 108.

Continuing with FIG. 1A, in the present embodiment, the gate 104 ispositioned substantially orthogonal to the surface of the substrate 108and bent at a 45 degree angle towards the top of the force applicator106. However, it should be understood that the gate 104 can bepositioned in essentially any fashion and bent in any angle so long asthe gate 104 can function to planarize the cleaning solution 110 on thesubstrate 108 surface. In one embodiment, the gate 104 is a solidstructure without an internal cavity region. In another embodiment, thegate 104 is a hollow structure. Some examples of materials that that thegate 104 can be made out of include glass, stainless steel, aluminum,ceramics, rubber, and polymers (e.g., Teflon™, polyvinyl alcohol,polyurethane, polytetrafluoroethylene, polyethylene terephthalate,polyvinylidine difluoride, polyetheretherketone, polyvinyl chloride,etc.). It should be appreciated, however, that the gate 104 can be madeof any material so long as the material is non-reactive with thecleaning solution 110 and does not hinder the planarization of thecleaning solution 110 on the surface of the substrate 108.

As depicted in the present embodiment, a cleaning solution 110 dispenser102 is positioned proximate to the leading edge of the force applicator106. As the force applicator 106 rotates, the dispenser 102 supplies themulti-phase cleaning solution 110 directly to the substrate surface. Inone embodiment, the solution 110 is applied directly to the forceapplicator 106. Then by virtue of the force applicator 106 rotation, thecleaning solution 110 is applied against the surface of the substrate108. In one embodiment, the dispenser 102 is configured to move inunison with the force applicator 106 and the gate 104 across thesubstrate surface during a cleaning operation. In one embodiment, theforce applicator 106 is configured to rotate towards the surface of thesubstrate 108. In another embodiment, force applicator 106 is configuredto rotate away from the top surface of the substrate 108. The rotationalvelocity of the force applicator 106 can be set to any value so long asthe cleaning solution 110 is applied to the substrate surface withsufficient force to effectuate the desired cleaning of the substratesurface without losing an unacceptable amount of the cleaning solution110.

FIG. 1B shows a top view of the apparatus, in accordance with oneembodiment of the present invention. As depicted in this embodiment, theforce applicator and gate 104 are shown to stretch lengthwise to coverthe entire diameter of the substrate 108. The dispenser 102 is shown asa nozzle that is positioned towards the midpoint of the force applicator106 and configured to supply the cleaning solution 110 to the leadingedge of the applicator 106. In one embodiment, the dispenser 102 is amanifold that stretches the entire length of the force applicator 106and configured to supply the cleaning solution 110 directly to thesubstrate surface. In another embodiment, the dispenser 102 is themanifold as described above and configured to supply the cleaningsolution 110 to both the substrate surface and the applicator 106.

As depicted in the present embodiment, the substrate 108 is rotated in acounter-clockwise direction as the force applicator 106 and gate 104moves across the surface of the substrate 108. In one embodiment, thesubstrate 108 is rotated in a clockwise direction as the forceapplicator 106 and gate 104 moves across the substrate surface.Typically, the substrate 108 rotates at between about 4 and 8 rotationsper minute (rpm).

FIG. 2A shows a cross-sectional view of a force applicator and gate, inaccordance with one embodiment of the present invention. As depicted inthis embodiment, the force applicator 106 includes a plurality ofbaffles 202 that protrude out from the applicator 106 and are alignedwith the axis of rotation 235 of the force applicator 106. The baffles202 are configured to drive the cleaning solution 110 against thesubstrate surface by supplying a sweeping action that carries and forcesthe cleaning solution 110 against the substrate surface. In oneembodiment, the baffles 202 are evenly spaced from one another. Inanother embodiment, the baffles 202 are randomly spaced from oneanother.

It should be appreciated that the baffles 202 can be designed so thatthey protrude out from the applicator 106 at any angle, relative to thelongitudinal surface of the force applicator 106, so long as the baffles202 can function to drive the cleaning solution 110 against thesubstrate surface with sufficient force to effectuate the desiredcleaning. In one embodiment, the force applicator 106 includes a seriesof channels that travel the length of the applicator 106 and serve thesame function as the baffles 202. In one embodiment, the baffles 202 areaffixed to the force applicator 106 using an adhesive material. Examplesof materials that can be used to make the baffles 202 include rubber,ceramics, polymers (i.e., Teflon™, polyvinyl alcohol, polyurethane,polytetrafluoroethylene, polyethylene terephthalate, polyvinylidinedifluoride, polyetheretherketone, polyvinyl chloride, etc.), and solidmetals (i.e., aluminum, steel, etc.).

Continuing with FIG. 2A, in the present embodiment, the gate 104 isplaced proximate to the force applicator 106 at a trailing position thatis far enough away from the baffles 202 so that the baffles 202 do notcontact the gate 104. Additionally, the force applicator 106 ispositioned so that the baffles 202 do not contact the surface of thesubstrate 108. Typically, the applicator 106 maintains a distance ofbetween about 0.1 mm and 100 mm off the substrate surface. The forceapplicator 106 is configured to rotate towards the substrate surface.

FIG. 2B is an illustration showing a side view of a force applicatorwith a straight line baffle pattern, in accordance with one embodimentof the present invention. In this embodiment, the baffles 202 are shownas stretching uninterrupted in linear fashion along the longitudinalsurface of the force applicator 106. It should be understood that thewidth (distance the baffle protrudes from the force applicator 106) andthickness of the baffles 202 can vary in accordance with the particularcleaning application that the force applicator 106 is utilized for. Inone embodiment, each baffle includes intermittent gaps or openings.

FIG. 2C is a depiction of a side view of a force applicator with adiagonal baffle pattern, in accordance with one embodiment of thepresent invention. In this embodiment, the baffles 202 are shown asdiagonal lines stretching along the length of the force applicator 106.It should be understood that the baffle patterns can take any form solong as the resulting baffle pattern can adequately drive a cleaningsolution 110 against the substrate surface with sufficient force toeffectuate the desired cleaning profile.

FIG. 3A is an illustration of a side view of an apparatus for uniformlyapplying a multi-phase cleaning solution across the surface of asubstrate 108, in accordance with one embodiment of the presentinvention. As depicted in this embodiment, the apparatus includes a gate104 that is affixed to the force applicator 106 via arm extensions 302that are operatively connected to the rotational axes on the edgesurfaces of the force applicator 106. The gate 104 has a partial annularshape that arches from just above the substrate surface to just over thetop surface of the force applicator 106. A cleaning solution dispenser102 is attached to the portion of the gate 104 positioned over the forceapplicator 106. The dispenser 102 is configured to supply a cleaningsolution 110 simultaneously to the applicator 106 and the substratesurface. In one embodiment, the dispenser 102 is detached from the gate104 and configured so that the position of the dispenser 102 can beadjusted depending on the requirements of the cleaning application.

As depicted herein, the arm extensions 302 are shown to be affixed totwo points on the gate 104 and the rotational axis 235 of the forceapplicator 106. The gate 104 and force applicator 106 move in unisonparallel to the substrate surface, uniformly applying a force (using theforce applicator 106) against the cleaning solution 110 and planarizing(using the gate 104) the cleaning solution 110 on the substrate surface.In one embodiment, the gate 104 is attached to the force applicator 106via a single point of contact. For example, the gate 104 can be attachedvia a single arm extension to the axis of rotation 235 on both sides ofthe force applicator 106. In another embodiment, the gate 104 isattached to the force applicator 106 via a plurality of arm extensions302 at a plurality of points on the gate 104. In one embodiment, the armextensions 302 are configured to enable the adjustment of the distanceof the gate 104 relative to the substrate surface. As discussed above,typically, the gate 104 is positioned so that the distance between thegate 104 and the surface of the substrate 108 is between about 0.1 mmand 5.0 mm.

FIG. 3B is an illustration showing a top view of an apparatus foruniformly applying a multi-phase cleaning solution across the surface ofa substrate, in accordance with one embodiment of the present invention.As depicted in this embodiment, the gate 104 is shown to be affixed tothe side surfaces of the leading edge of the force applicator 106. Twocleaning solution dispensers 102 are positioned proximate to the forceapplicator 106 and are configured to supply the cleaning solution 110 tothe substrate surface adjacent to the force applicator 106. In thisembodiment, the gate 104 is shown to overlap the two sides of the forceapplicator 106. It should be understood that the length of the gate 104relative to the force applicator 106 may vary so long as the gate 104can adequately function to planarize the cleaning solution 110 acrossthe entire length of the substrate 108 as the gate 104 moves across thesubstrate surface.

FIG. 4A is an illustration of a side view of an apparatus for uniformlyapplying a multi-phase cleaning solution 110 across the surface of asubstrate 108, in accordance with one embodiment of the presentinvention. In this embodiment, the apparatus includes a force applicator402 and a gate 104. The force applicator 402 includes two cylindricaldrums that are encased by a flexible sheet. The cylindrical drums areconfigured to rotate in unison and impart a force to the flexible sheetso that the sheet rotates around both drums. It should be appreciatedthat the force applicator 402 can include any number of drums so long asthe resulting applicator 402 can function to supply enough force toeffectuate the desired cleaning of the substrate surface. Examples ofmaterials that can be used to make the flexible sheet include polymers(e.g Teflon™, polyvinyl alcohol, polyurethane, polytetrafluoroethylene,polyethylene terephthalate, polyvinylidine difluoride,polyetheretherketone, polyvinyl chloride, etc.) and rubber. However, itshould be understood that essentially any flexible material can be usedto make the sheet so long as the material does not chemically react withthe cleaning solution 110 and can effectuate the desired cleaning of thesubstrate surface.

FIG. 4B is an illustration of a top view of an apparatus for uniformlyapplying a multi-phase cleaning solution across the surface of asubstrate, in accordance with one embodiment of the present invention.As depicted in this embodiment, force applicator 402 and gate 104 areshown to stretch lengthwise to cover the entire diameter of thesubstrate 108. The cleaning solution manifold 420 is positioned adjacentto the force applicator 402 and also stretches lengthwise to cover theentire diameter of the substrate surface. In one embodiment, themanifold stretches lengthwise to cover only a portion of the diameter ofthe substrate surface. As depicted, the manifold 420 is configured tosupply the cleaning solution 110 directly to the substrate surface asthe substrate 108 is being rotated at between about 4 to 8 revolutions aminute. In one embodiment, the manifold 420 is configured to supply thecleaning solution 110 to both the substrate surface and the forceapplicator 402.

In one embodiment, the manifold 420 is configured to be attached to theforce applicator 402 and to move in unison with the applicator 402 andgate 104 across the substrate 108. In another embodiment, the manifold420 is detached from the force applicator 402 but configured to move inunison with the force applicator 402 and gate 104 across the substrate108.

FIG. 5A is an illustration of a side view of a plurality of poweredrollers supporting and rotating a substrate as a force applicator andgate uniformly applies a multi-phase cleaning solution across thesurface of the substrate, in accordance with one embodiment of thepresent invention. In this embodiment, the substrate 108 is shown asbeing supported by a plurality of powered rollers 502 that areconfigured to impart a set rotational velocity to the substrate 108 asthe force applicator 106 and gate 104 moves across the surface of thesubstrate 108. Typically, the rollers 502 are configured to rotate thesubstrate 108 at between about 4 and 8 rpm depending on the requirementsof the cleaning application.

FIG. 5B is an illustration of a top view of a set of four poweredrollers supporting and rotating a substrate as a force applicator andgate uniformly applies a multi-phase cleaning solution across thesurface of the substrate, in accordance with one embodiment of thepresent invention. As depicted in this embodiment, the substrate 108 issupported by a set of four powered rollers 502 spaced along thecircumference of the substrate 108. It should be understood that feweror greater numbers of powered rollers 502 may be utilized so long as thesubstrate 108 is adequately supported during cleaning operations and therollers 502 are capable of imparting the required rotational velocity tothe substrate 108.

FIG. 5C is an illustration of a side view of a vacuum chuck used tosupport and rotate a substrate as a force applicator and gate uniformlyapplies a multi-phase cleaning solution across the surface of thesubstrate, in accordance with one embodiment of the present invention.As depicted in this embodiment, the substrate 108 is supported by avacuum chuck 504 that is configured to impart a rotational velocity ofbetween about 4 to 8 rpm to the substrate 108 and provide a vacuumagainst the bottom surface of the substrate 108 to bind the substrate108 to the surface of the chuck 504 during cleaning operations. In oneembodiment, the chuck 504 emits an electrostatic force to bind thesubstrate 108 to the surface of the chuck 504 during cleaning. Inanother embodiment, the chuck 504 provides a layer of adhesive materialthat binds to the bottom of the substrate 108.

FIG. 6A is an illustration of a top view of a system for cleaning asubstrate having surface contaminants, in accordance with one exemplaryembodiment of the present invention. In this embodiment, the systemincludes three distinct cleaning zones. The first zone includes a pairof powered rollers 502 affixed to the base of the system containmenthousing 620, a force applicator 106, a gate 104 affixed to the trailingedge of a force applicator 106, a manifold 420 affixed to the leadingedge of the force applicator 106, and a tandem roller unit 603. Thesecond zone includes six rinse nozzles 610 that are positioned above thesubstrate 108 and configured to dispense a liquid to rinse a cleaningsolution 110 from the top surface of the substrate 108 as the substrate108 moves underneath the nozzles 610. Examples of liquids that can bedispensed by the nozzles 610 include Deionized Water (DIW), AmmoniumPeroxide (NH₄OH), Hydrogen Peroxide (H₂O₂), and SC-1 solution(NH₄OH/H₂O₂/H₂O). However, it should be understood that essentially anyliquid can be used so long as the liquid can adequately remove thecleaning solution 110 from the substrate surface per the requirements ofthe cleaning operation. The third zone includes a plurality of proximityhead units 612 that are configured to effectuate a final cleaning anddrying of the top and/or bottom surfaces of the substrate 108. Adescription of proximity head units and their method of operation can befound in co-pending application Ser. No. 10/261,839 entitled, “Methodand Apparatus for Drying Semiconductor Wafer Surfaces Using a Pluralityof Inlets and Outlets Held in Close Proximity to the Wafer Surfaces”published in 2004-0069329A1, co-pending application Ser. No. 10/330,843entitled “Meniscus, Vacuum, IPA Vapor, Drying Manifold” published in2004-0060580A1 as well as U.S. patents including 6,988,327, 6,954,993,and 6,988,326 all assigned to Lam Research Corporation and areincorporated herein by reference.

In one embodiment, the force applicator 106, gate 104, rinse nozzles610, and proximity head units 612 are configured to operate within asingle cleaning zone. It should be appreciated that the systemcontainment housing 620 can be configured to have cleaning zones thatare different from those described in this embodiment. The types (e.g.,bevel edge cleaning, surface cleaning with brushes, etc.) and numbers ofcleaning zones that can be incorporated into the system housing 620 islimited only by their operational compatibility with the forceapplicator 106/gate 104 unit and the space available in the systemcontainment housing 620.

As depicted in FIG. 6A, a substrate carrier 604 is provided whichincludes an opening sized to fit a substrate 108 and includes four clips606 that are configured to support the substrate 108 during transportbetween one zone and another. The substrate carrier 604 moves on top oftwo guide tracks 602 that run the length of the system containmenthousing across all three cleaning zones. In one embodiment, thesubstrate carrier 604 does not have an opening for the substrate 108 butinstead has a plurality of clips 606 that are configured to support thesubstrate 108 in an elevated profile off the top surface of thesubstrate carrier 604. In one embodiment, the carrier 604 runs on aplurality of powered wheels that are configured to move the carrier 604from one cleaning zone to the next. In another embodiment, the carrier604 is driven by a motorized chain belt system mounted adjacent to oneof the guide tracks 602 in the containment housing.

Continuing with FIG. 6A, the force applicator with the affixed gate andmanifold dispenser is mounted on a mechanical arm 605 that is attachedto the side wall of the containment housing. The mechanical arm 605 isconfigured to move the applicator 106, gate 104, and manifold dispenser420 in unison across the substrate surface. Concurrent with movingacross the substrate 108, the manifold dispenser is configured to supplya cleaning solution 110 to the substrate surface proximate to theleading edge of the applicator 106. As the applicator 106 comes intocontact with the cleaning solution 110, the applicator 106 is configuredto rotate and supply a force against the cleaning solution 110 uniformlyacross the diameter of the substrate 108. The gate 104 affixed to thetrailing edge of the applicator 106 is configured to planarize thecleaning solution 110 to a predetermined height off the substratesurface as it moves across the substrate 108. In one embodiment, themotorized arm 605 is configured to allow adjustment of the distance(typically between about 0.1 mm and 100 mm) that the applicator 106 andgate 104 sits above the substrate surface. In one embodiment, theapplicator 106, gate 104, and manifold dispenser are mounted on amotorized carrier 604 that is configured to move translationally acrossthe substrate surface.

As depicted in the embodiment shown in FIG. 6A, a plurality of chemicalfeed lines are attached to the manifold dispenser 420 and the mechanicalarm 605. The chemical feed lines are configured to supply the cleaningsolution 110 that is dispensed by the manifold dispenser. In oneembodiment, the chemical feed lines are configured to supply cleaningsolution 110 to one or more spray dispensers that are affixed to theforce applicator 106.

Still with FIG. 6A, the tandem roller unit 603 includes two rollers andis affixed to a mechanical arm 605. The mechanical arm 605 is configuredto rotate the unit towards the base of the containment housing and alignthe rollers to the edge of the substrate 108. The rollers are configuredto provide support for the substrate 108. In one embodiment, the rollersare powered and configured to impart a rotational velocity to thesubstrate 108 of between about 4 and 8 rpm. In another embodiment, therollers are not powered and are configured to rotate freely as thesubstrate 108 is rotated by the powered rollers 502.

FIG. 6B is an illustration of a top view of a system for cleaning asubstrate having surface contaminants, in accordance with one embodimentof the present invention. As with the system discussed above, the systemdepicted in this embodiment includes three distinct cleaning zones. Thefirst zone includes a force applicator 106, a gate 104 positioned at thetrailing edge of a force applicator 106, and two cleaning solutiondispensers 102 positioned adjacent to the leading edge of the forceapplicator 106. The second cleaning zone includes six rinse nozzles thatare positioned above the substrate surface and configured to dispense aliquid to rinse a cleaning solution 110 off the top surface of thesubstrate 108 as the substrate 108 moves underneath the nozzles. Thethird zone includes proximity head units that are configured toeffectuate a final cleaning and drying of the top and/or bottom surfacesof the substrate 108.

As depicted in FIG. 6B, the force applicator 106 is attached tomotorized drive units 608 on both sides of the system containment unit.The motorized drive units 608 are configured to rotate the forceapplicator 106 towards the substrate surface during a cleaningoperation. As the substrate carrier 604 transports the substrate 108translationally from the first cleaning zone to the second cleaningzone, the force applicator 106 is configured to uniformly apply a forceagainst the cleaning solution 110 on the substrate surface. In oneembodiment, the motorized drive units 608 are configured to enableadjustment of the vertical distance that the force applicator 106 is offthe top surface of the substrate 108. Typically, the distance maintainedbetween the force applicator 106 and substrate surface during a cleaningoperation is between about 0.1 mm and 100 mm. In another embodiment, theposition of the force applicator 106 is fixed and cannot be adjusted. Inyet another embodiment, the substrate carrier 604 is configured to allowthe adjustment of the distance between the carrier 604/substrate 108 andthe force applicator 106.

Continuing with FIG. 6B, the gate 104 is positioned at the trailingpoint adjacent to the force applicator 106. As depicted in thisembodiment, the gate 104 is affixed to both sides of the systemcontainment unit. The gate 104 is configured to planarize the cleaningsolution 110 on the substrate surface as the carrier 604 moves thesubstrate 108 translationally from the first cleaning zone to the secondcleaning zone. In one embodiment, the gate 104 is configured to enableadjustment of the vertical distance between the gate 104 and the topsurface of the substrate 108. Typically, the distance between the gate104 and the substrate surface is maintained at a range of between about0.1 mm and 5.0 mm. In another embodiment, the position of the gate 104is fixed and cannot be adjusted.

FIG. 6C is an illustration of a side view of a system for cleaning asubstrate having surface contaminants, in accordance with one embodimentof the present invention. As depicted herein, the substrate 108 issupported by clips 606 attached to a substrate carrier 604. Thesubstrate carrier 604 includes a plurality of wheels that are configuredto transport the carrier 604 on guide tracks 602 translationally fromone cleaning zone to the next. In one embodiment the carrier 604 isconfigured to supply the power to the rotate the wheels. In a differentembodiment, the carrier 604 is attached to a chain drive that pulls thecarrier 604 along on the guide track.

Continuing with FIG. 6C, as discussed above, the first cleaning zone 630includes a cleaning solution dispenser 102, force applicator 106, and agate 104. The dispenser supplies the cleaning solution 110 directly tothe substrate surface on the leading edge of the force applicator 106.As the carrier 604 transports the substrate 108 along the guide track,the force applicator 106 applies a force against the cleaning solution110 and the gate 104 at the trailing point of the force applicator 106simultaneously planarizes the cleaning solution 110 to a desired heightoff the substrate surface.

As the substrate 108 is transported to the second cleaning zone 632, aplurality of spray dispensers spread across over the entire diameter ofthe substrate 108 supplies fluids to the rinse off the cleaning solution110 from the substrate surface. The rinsate is collected in a catchbasin at the base of the system containment unit 614. Typically,deionized water (DIW) is used as the rinsing liquid for thisapplication. Moving from the second cleaning zone 632 into the thirdcleaning zone 634, proximity head units 612 are positioned above andbelow the substrate surface to provide the final rinse and drying of thesubstrate surfaces. In one embodiment, the proximity head units 612 areconfigured to be long enough to provide coverage of the entire diameterof the substrate 108.

FIG. 7 shows a flow chart of a method for uniformly applying amulti-phase cleaning solution (i.e., foam, emulsions, etc.) across thesurface of a substrate, in accordance with one embodiment of the presentinvention. Diagrams of the apparatus and system utilized in this methodare shown in FIGS. 1A, 1B, 6A, and 6B. Method 700 begins with operation702 where a cleaning solution is applied to the surface of a substrate.As discussed previously, the substrate can be either a semiconductorwafer or a LCD flat panel, or other material requiring critical removalof discrete particles. The cleaning solution has a dispersed phase, acontinuous phase and solids dispersed throughout the continuous phase.In one embodiment, the cleaning solution is supplied by a cleaningsolution dispenser positioned proximate to the leading edge of a forceapplicator 106. In another embodiment, the cleaning solution is suppliedby a manifold dispenser that stretches to match the length of the forceapplicator.

In one embodiment, the substrate is supported and rotated at betweenabout 4 and 8 rpm using a plurality of powered rollers while thecleaning solution is being applied. In a different embodiment, thesubstrate is supported and rotated using a vacuum chuck. The vacuumchuck configured to provide a vacuum against the bottom surface of thesubstrate to prevent the substrate from moving during the rotationand/or cleaning operations.

The method then proceeds to operation 704 where a force is appliedagainst the cleaning solution such that the force partially controls thecontainment of the solution and subjects the cleaning solution to asubstantially planar profile over the surface of the substrate. A forceapplicator supplies the force and a gate planarizes the cleaningsolution over the substrate surface as the applicator and gate moves inunison across the substrate surface. In one embodiment, the position ofthe force applicator is configured to be fully adjustable to a distancebetween about 0.1 mm and 100 mm from the surface of the substrate. Inanother embodiment, the position of the gate is configured to be fullyadjustable to a distance between about 0.1 mm and 5.0 mm from thesubstrate surface. In one embodiment, the applicator and gate arepositioned at approximately the same distance form the substratesurface.

Although a few embodiments of the present invention have been describedin detail herein, it should be understood, by those of ordinary skill,that the present invention may be embodied in many other specific formswithout departing from the spirit or scope of the invention. Therefore,the present examples and embodiments are to be considered asillustrative and not restrictive, and the invention is not to be limitedto the details provided therein, but may be modified and practicedwithin the scope of the appended claims.

What is claimed is:
 1. A system for cleaning a substrate having surfacecontaminants thereon, comprising: a carrier capable of holding thesubstrate and movably coupled to a pair of guide tracks extending alonga length of the system; a cleaning station including a force applicatorand a gate, wherein the force applicator has an applicator length and isoperatively connected to the cleaning station above a surface of thecarrier and the pair of guide tracks, wherein the force applicator isrotatable, the force applicator is set to a first height off the surfaceof the carrier as the substrate is being cleaned, the force applicatorhaving a hollow structure with a plurality of internal channels andopenings dispersed throughout the applicator length of the forceapplicator, the plurality of channels and openings configured todispense a cleaning solution to a surface of the substrate, wherein thegate is affixed to a trailing edge of the force applicator, the gate setto a second height off the surface of the carrier, the gate having agate length that extends to at least span the applicator length.
 2. Thesystem of claim 1, further includes one or more motorized drive units,the motorized drive units attached to the force applicator so as toadjust a vertical distance of the force applicator from the surface ofthe carrier and to rotate the force applicator toward a surface of thesubstrate when present, during cleaning.
 3. The system of claim 1,wherein the gate is a hollow structure.
 4. The system of claim 1,wherein the gate is a solid structure without any internal cavityregion.
 5. The system of claim 1, wherein the force applicator includesa plurality of baffles distributed along a longitudinal surface of theforce applicator, the baffles configured to apply a force against thecleaning solution.
 6. The system of claim 1, wherein the gate is affixedto the trailing edge of the force applicator via one or more armextensions, wherein the arm extensions are operatively connected torotational axis at one or more edge surfaces of the force applicator. 7.The system of claim 1, wherein the gate has a partial annular shape withan arch beginning from above the substrate surface to cover a topsurface of the force applicator, the arch of the gate defined to providesufficient space for the force applicator to rotate.
 8. The system ofclaim 1, wherein the force applicator includes a separate dispenser fordispensing a fluid to the surface of the substrate, the dispenserdisposed at a leading edge of the force applicator.
 9. The system ofclaim 1, wherein the first height and the second height are equidistantfrom the surface of the carrier.
 10. The system of claim 1, wherein thefirst height is at a higher height from the surface of the carrier thanthe second height.
 11. A system for cleaning a substrate having surfacecontaminants thereon, comprising: a carrier configured to hold thesubstrate; a cleaning station including a force applicator and a gate,wherein the force applicator has an applicator length and is operativelyconnected to the cleaning station above a surface of the carrier,wherein the force applicator is rotatable, the force applicator is setto a first height off the surface of the carrier as the substrate isbeing cleaned, the force applicator having a hollow structure with aplurality of internal channels and openings dispersed throughout theapplicator length of the force applicator, the plurality of channels andopenings configured to dispense a cleaning solution to a surface of thesubstrate, wherein the gate is affixed to a trailing edge of the forceapplicator, the gate set to a second height off the surface of thecarrier, the gate having a gate length that extends to at least span theapplicator length.
 12. The system of claim 11, wherein the carrier is avacuum chuck.
 13. The system of claim 11, wherein the carrier isconfigured to hold the substrate and to translationally move thesubstrate along a length of the system using a pair of guide tracksextending the length of the system.
 14. The system of claim 11, whereinthe force applicator includes a plurality of baffles disposed along alongitudinal surface of the force applicator, the plurality of bafflesaligned with an axis of rotation of the force applicator, the bafflesconfigured to apply a force against the cleaning solution.
 15. Thesystem of claim 11, wherein the gate has a partial annular shape with anarch beginning from above the substrate surface to cover a top surfaceof the force applicator, the arch of the gate defined to providesufficient space for the force applicator to rotate.
 16. The system ofclaim 11, wherein the first height and the second height are equidistantfrom the surface of the carrier.
 17. The system of claim 11, wherein thefirst height is at a higher height from the surface of the carrier thanthe second height.